ABSTRACT
15 extracted premolars were selected and randomly divided into 3 groups, with 5 in each group. MANI TF-13 bur、TR13-EF bur and the dental pneumatic ultrasonic hand-piece were respectively used to dispose the shoulder. 15 Zirconium dioxide full crowns were made. The shoulder marginal microleakage was observed by staining method. Dental pneumatic ultrasonic hand-piece showed the best anti-mic-roleakage effect in shoulder refinement.
ABSTRACT
OBJECTIVE To investigate the disinfection efficacy of dental high-speed hand-pieces contaminated by HBV with the method of pressure steam sterilizer.METHODS Taking 50 oral clinical patients randomly,and three group-samples which included saliva,hand-pieces contaminated by clinical operation and disinfected by pressure steam sterilizing were collected,then the samples were detected HBsAg and HBV DNA,respectively.RESULTS There were 95% of the saliva samples being HBsAg positive,the positive rate of the high-speed hand-pieces contaminated by clinical operation was lower than the saliva samples,and the positive rate of the hand-piece disinfected by pressure steam sterilizing was the lowest.HBV DNA was undetectable in the sample before or after disinfected hand-pieces used in patients′ saliva which HBsAg s/co value higher than 5.0.CONCLUSIONS Pressure steam sterilizing is effective to reduce the contaminated HBV on hand-pieces,but the biology test should be taken to demonstrate whether the complete sterilizing is achieved.
ABSTRACT
OBJECTIVE To investigate the factors influencing the effects of disinfection of HBV on dental hand piece. METHODS After polluted with HBV positive serum,the dental hand piece was disinfected with sterilizer at the condition of 134℃ for 5 minutes according different treatment procedures.The samples were then taken and detected HBsAg by the automatic enzyme immune analyzer using the third generation EIA agent.The efficacy of disinfection of HBV was presented by the reaction of HBsAg detection. RESULTS If the dental hand piece was sterilized directly not cleansed using clean water after pollution and dried in room temperature,there were 96.87% of the samples being HBsAg positive,and the polluted but dried hand piece,even cleansed there were 87.5% of positive result, even if prolonged the time of sterilization and the frequencies of vacuumization,the HBsAg positive rate of the sample was still up to 56.25%.But if the hand piece was irrigated and cleansed immediately after pollution and sterilized,all samples were HBsAg negative. CONCLUSIONS Whether or not cleansed immediately is the most important factor influencing the efficacy of hand piece sterilization after pollution.